Mobile device and optical imaging lens thereof

ABSTRACT

Present embodiments provide for a mobile device and an optical imaging lens thereof. The optical imaging lens comprises five lens elements positioned sequentially from an object side to an image side. Through controlling the convex or concave shape of the surfaces and/or the refracting power of the lens elements, the optical imaging lens shows better optical characteristics and the total length of the optical imaging lens is shortened.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/121,452, filed on Sep. 4, 2018, which is a continuation of U.S.patent application Ser. No. 15/332,868, filed on Oct. 24, 2016, now U.S.Pat. No. 10,120,166, which is a continuation of U.S. patent applicationSer. No. 14/954,655, filed on Nov. 30, 2015, now U.S. Pat. No.9,513,468, which is a continuation of U.S. patent application Ser. No.14/543,808, filed on Nov. 17, 2014, now U.S. Pat. No. 9,229,197, whichis a continuation of U.S. patent application Ser. No. 13/847,456, filedon Mar. 19, 2013, now U.S. Pat. No. 8,934,181, which claims priority toTaiwan Patent Application No. 101140812, filed on Nov. 2, 2012; thecontents of which are hereby incorporated by reference in their entiretyfor all purposes.

TECHNICAL FIELD

The present invention relates to a mobile device and an optical imaginglens thereof, and particularly, relates to a mobile device applying anoptical imaging lens having five lens elements and an optical imaginglens thereof.

BACKGROUND OF THE INVENTION

Dimension reduction is the major consideration for design an opticalimaging lens in recent years. When reducing the length of the opticalimaging lens, however, achieving good optical characteristics becomes achallenging problem.

U.S. Pat. Nos. 7,480,105, 7,639,432, 7,486,449, and 7,684,127 alldisclosed an optical imaging lens constructed with an optical imaginglens having five lens elements. The transition of refracting powers ofthe first three lens elements in U.S. Pat. No. 7,480,105 isnegative-positive-negative, and those in U.S. Pat. Nos. 7,639,432,7,486,449, and 7,684,127 are negative-positive-positive,negative-negative-positive, and negative-negative-positive respectively.However, such configurations still fail to achieve good opticalcharacteristics, and further, fail to reduce the size of the wholesystem, because the lengths of the optical imaging lenses thereof fallinto the range of 10˜18 mm.

U.S. Patent Publication No. 2011/0013069, and 2011/0249346, and U.S.Pat. No. 8,000,030 all disclosed an optical imaging lens constructedwith an optical imaging lens having five lens elements. The transitionof refracting powers of the first three lens elements in these threedocuments is the better positive-negative-negative. However, theconfigurations of the lens elements thereof are unfavorable forimproving the optical aberrations and meanwhile shortening the length ofthe optical imaging lens, therefore, for achieving better imagingquality, the lengths of the imaging lens are unable to be shortened. Forexample, the lengths of some imaging lens reach 6.0 mm, and this needsfor improvement.

Therefore, there is needed to develop optical imaging lens with ashorter length, while also having good optical characters.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a mobile device and anoptical imaging lens thereof. With controlling the convex or concaveshape and/or the refracting power of the surfaces of the lens elements,the length of the optical imaging lens is shortened and meanwhile thegood optical characteristics, and system functionality are sustained.

In an exemplary embodiment, an optical imaging lens comprises,sequentially from an object side to an image side, comprises first,second, third, fourth and fifth lens elements, each of said first,second, third, fourth and fifth lens elements having an object-sidesurface facing toward the object side and an image-side surface facingtoward the image side, wherein: the first lens element has positiverefracting power, and the object-side surface thereof is a convexsurface; the second lens element has negative refracting power; thethird lens element has negative refracting power; the object-sidesurface of the fifth lens element comprises a concave portion in avicinity of the optical axis, and the image-side surface of the fifthlens element comprises a convex portion in a vicinity of a periphery ofthe fifth lens element; and the optical imaging lens as a whole has onlythe five lens elements having refracting power.

In another exemplary embodiment, some equation(s), such as thoserelating to the difference or the ratio among parameters can be takeninto consideration. For example, the sum of all four air gaps from thefirst lens element to the fifth lens element along the optical axis,AAG, and a central thickness of the fifth lens element along the opticalaxis, CT₅, could be controlled to satisfy the equation as follows:AAG/CT ₅≥3.0  Equation (1); or

An air gap between the second lens element and the third lens elementalong the optical axis, AGL₂₃, and an air gap between the fourth lenselement and the fifth lens element along the optical axis, AGL₄₅, couldbe controlled to satisfy the equation as follows:0≤AGL ₂₃-AGL ₄₅≤0.4 (mm)  Equation (2); or

An effective focal length of the optical imaging lens, EFL, and thetotal thickness of all five lens elements, ALT, could be controlled tosatisfy the equation(s) as follows:EFL/ALT≥1.8  Equation (3); orEFL/ALT≥1.9  Equation (3′); or

A central thickness of the fourth lens element along the optical axis,CT₄, and a back focal length of the optical imaging lens, BFL, could becontrolled to satisfy the equation(s) as follows:CT ₄ /BFL≤0.7  Equation (4); orCT ₄ /BFL≤0.5  Equation (4′); or

ALT and BFL could be controlled to satisfy the equation(s) as follows:ALT/BFL≤2.0  Equation (5); orALT/BFL≤1.5  Equation (5′); or

CT₄ and AGL₂₃ could be controlled to satisfy the equation as follows:CT ₄ /AGL ₂₃≤3.0  Equation (6).

Aforesaid exemplary embodiments are not limited and could be selectivelyincorporated in other embodiments described herein.

In some exemplary embodiments, more details about the convex or concavesurface structure could be incorporated for one specific lens element orbroadly for plural lens elements to enhance the control for the systemperformance and/or resolution. For example, the object-side surface ofthe fourth lens element could comprise a concave portion in a vicinityof a periphery of the fourth lens element, or the object-side surface ofthe second lens element could comprise a convex portion in a vicinity ofa periphery of the second lens element.

In another exemplary embodiment, a mobile device comprising a housingand a photography module positioned in the housing is provided. Thephotography module comprises any of aforesaid example embodiments ofoptical imaging lens, a lens barrel, a module housing unit, a substrate,and an image sensor. The lens barrel is for positioning the opticalimaging lens, the module housing unit is for positioning the lensbarrel, the substrate is for positioning the module housing unit, andthe image sensor is positioned at the image-side of the optical imaginglens.

In some exemplary embodiments, the module housing unit optionallycomprises a seat element for positioning the lens barrel and movingalong with the optical axis of the optical imaging lens.

Through controlling the convex or concave shape of the surfaces and/orthe refraction power of the lens element(s), the mobile device and theoptical imaging lens thereof in exemplary embodiments achieve goodoptical characters and effectively shorten the length of the opticalimaging lens.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments will be more readily understood from the followingdetailed description when read in conjunction with the appended drawing,in which:

FIG. 1 is a cross-sectional view of a first embodiment of an opticalimaging lens having five lens elements according to the presentdisclosure;

FIG. 2 is a chart of longitudinal spherical aberration and other kindsof optical aberrations of a first embodiment of the optical imaging lensaccording to the present disclosure;

FIG. 3 is a cross-sectional view of a lens element of the opticalimaging lens of an example embodiment of the present disclosure;

FIG. 4 is a table of optical data for each lens element of a firstembodiment of an optical imaging lens according to the presentdisclosure;

FIG. 5 is a table of spherical data of a first embodiment of the opticalimaging lens according to the present disclosure;

FIG. 6 is a cross-sectional view of a second embodiment of an opticalimaging lens having five lens elements according to the presentdisclosure;

FIG. 7 is a chart of longitudinal spherical aberration and other kindsof optical aberrations of a second embodiment of the optical imaginglens according to the present disclosure;

FIG. 8 is a table of optical data for each lens element of the opticalimaging lens of a second embodiment of the present disclosure;

FIG. 9 is a table of spherical data of a second embodiment of theoptical imaging lens according to the present disclosure;

FIG. 10 is a cross-sectional view of a third embodiment of an opticalimaging lens having five lens elements according to the presentdisclosure;

FIG. 11 is a chart of longitudinal spherical aberration and other kindsof optical aberrations of a third embodiment of the optical imaging lensaccording the present disclosure;

FIG. 12 is a table of optical data for each lens element of the opticalimaging lens of a third embodiment of the present disclosure;

FIG. 13 is a table of a spherical data of a third embodiment of theoptical imaging lens according to the present disclosure;

FIG. 14 is a cross-sectional view of a fourth embodiment of an opticalimaging lens having five lens elements according to the presentdisclosure;

FIG. 15 is a chart of longitudinal spherical aberration and other kindsof optical aberrations of a fourth embodiment of the optical imaginglens according the present disclosure;

FIG. 16 is a table of optical data for each lens element of the opticalimaging lens of a fourth embodiment of the present disclosure;

FIG. 17 is a table of a spherical data of a fourth embodiment of theoptical imaging lens according to the present disclosure;

FIG. 18 is a cross-sectional view of a fifth embodiment of an opticalimaging lens having five lens elements according to the presentdisclosure;

FIG. 19 is a chart of longitudinal spherical aberration and other kindsof optical aberrations of a fifth embodiment of the optical imaging lensaccording the present disclosure;

FIG. 20 is a table of optical data for each lens element of the opticalimaging lens of a fifth embodiment of the present disclosure;

FIG. 21 is a table of a spherical data of a fifth embodiment of theoptical imaging lens according to the present disclosure;

FIG. 22 is a cross-sectional view of a sixth embodiment of an opticalimaging lens having five lens elements according to the presentdisclosure;

FIG. 23 is a chart of longitudinal spherical aberration and other kindsof optical aberrations of a sixth embodiment of the optical imaging lensaccording the present disclosure;

FIG. 24 is a table of optical data for each lens element of the opticalimaging lens of a sixth embodiment of the present disclosure;

FIG. 25 is a table of a spherical data of a sixth embodiment of theoptical imaging lens according to the present disclosure;

FIG. 26 is a table for the values of AAG/CT₅, AGL₂₃-AGL₄₅, EFL/ALT,CT₄/BFL, ALT/BFL and CT₄/AGL₂₃ of all six example embodiments;

FIG. 27 is a structure of an example embodiment of a mobile device;

FIG. 28 is a partially enlarged view of the structure of another exampleembodiment of a mobile device.

DETAILED DESCRIPTION OF THE INVENTION

For a more complete understanding of the present disclosure and itsadvantages, reference is now made to the following description taken inconjunction with the accompanying drawings, in which like referencenumbers indicate like features. Persons having ordinary skill in the artwill understand other varieties for implementing example embodiments,including those described herein. The drawings are not limited tospecific scale and similar reference numbers are used for representingsimilar elements. As used in the disclosures and the appended claims,the terms “example embodiment,” “exemplary embodiment,” and “presentembodiment” do not necessarily refer to a single embodiment, although itmay, and various example embodiments may be readily combined andinterchanged, without departing from the scope or spirit of the presentinvention. Furthermore, the terminology as used herein is for thepurpose of describing example embodiments only and is not intended to bea limitation of the invention. In this respect, as used herein, the term“in” may include “in” and “on”, and the terms “a”, “an” and “the” mayinclude singular and plural references. Furthermore, as used herein, theterm “by” may also mean “from”, depending on the context. Furthermore,as used herein, the term “if” may also mean “when” or “upon”, dependingon the context. Furthermore, as used herein, the words “and/or” mayrefer to and encompass any and all possible combinations of one or moreof the associated listed items.

Example embodiments of an optical imaging lens may comprise an aperturestop, a first lens element, a second lens element, a third lens element,a fourth lens element, and a fifth lens element, each of the lenselements has an object-side surface facing toward the object side and animage-side surface facing toward the image side. These lens elements maybe arranged sequentially from an object side to an image side, andexample embodiments of the lens as a whole may comprise the five lenselements having refracting power. In an example embodiment: the firstlens element has positive refracting power, and the object-side surfacethereof is a convex surface; the second lens element has negativerefracting power; the third lens element has negative refracting power;the object-side surface of the fifth lens element comprises a concaveportion in a vicinity of the optical axis, and the image-side surface ofthe fifth lens element comprises a convex portion in a vicinity of aperiphery of the fifth lens element; and the optical imaging lens as awhole has only the five lens elements having refracting power.

Preferably, the lens elements are designed in light of the opticalcharacteristics and the length of the optical imaging lens. For example,the first lens element having positive refracting power provides thelight converge ability required in the optical imaging lens. Both thesecond lens element and the third lens element having negativerefracting power could eliminate the aberration of the optical lens.With a further concave portion in a vicinity of the optical axis on theobject-side surface of the fifth lens element and a convex portion in avicinity of a periphery on the image-side surface thereof, theaberration of the optical lens could be eliminated. Additionally, if thesecond lens element is designed to have convex portion in a vicinity ofa periphery of the second lens element on the object-side surfacethereof and/or the fourth lens element is designed to have a concaveportion in a vicinity of a periphery of the fourth lens element on theobject-side surface thereof, it could assist in reducing aberration aswell.

In another exemplary embodiment, other related parameters, such as acentral thickness of a lens element along the optical axis and or theratio among a central thickness of a lens element along the optical axisand the sum of all air gaps. For example, the sum of all four air gapsfrom the first lens element to the fifth lens element along the opticalaxis, AAG, and a central thickness of the fifth lens element along theoptical axis, CT₅, could be controlled to satisfy the equation asfollows:AAG/CT ₅≥3.0  Equation (1); or

An air gap between the second lens element and the third lens elementalong the optical axis, AGL₂₃, and an air gap between the fourth lenselement and the fifth lens element along the optical axis, AGL₄₅, couldbe controlled to satisfy the equation as follows:0≤AGL ₂₃-AGL ₄₅≤0.4 (mm)  Equation (2); or

An effective focal length of the optical imaging lens, EFL, and thetotal thickness of all five lens elements, ALT, could be controlled tosatisfy the equation(s) as follows:EFL/ALT≥1.8  Equation (3); orEFL/ALT≥1.9  Equation (3′); or

A central thickness of the fourth lens element along the optical axis,CT₄, and a back focal length of the optical imaging lens, BFL, could becontrolled to satisfy the equation(s) as follows:CT ₄ /BFL≤0.7  Equation (4); orCT ₄ /BFL≤0.5  Equation (4′); or

ALT and BFL could be controlled to satisfy the equation(s) as follows:ALT/BFL≤2.0  Equation (5); orALT/BFL≤1.5  Equation (5′); or

CT₄ and AGL₂₃ could be controlled to satisfy the equation as follows:CT ₄ /AGL ₂₃≤3.0  Equation (6).

Aforesaid exemplary embodiments are not limited and could be selectivelyincorporated in other embodiments described herein.

Reference is now made to equation (1). The value of AAG/CT₅ ispreferable greater than or equal to 3 to satisfy equation (1). This isbecause if the thickness of the fifth lens element along the opticalaxis is thin enough (i.e. CT₅ is small enough), and a convex portion ina vicinity of a periphery of the fifth lens element on the image-sidesurface thereof is formed, the refracting power around the optical axisand the periphery will be different to converge the light on the sameplane to improve the image quality. Although AAG and CT₅ is shrank tomeet modern thinner-and-slimer design, if CT₅ is shrank in a more ratethan AAG is (i.e. AAG is bigger), the effect to improve the imagequality is quite well. Additionally, the value of AAG/CT₅ is suggestedto within 3˜10.

Reference is now made to equation (2). The value of AGL₂₃-AGL₄₅ ispreferable greater than or equal to 0 (mm), i.e. the air gap between thesecond and third lens elements is greater than that between the fourthand fifth lens element. This is because the negative refracting power ofthe second lens element for dispersing light requires more distancebetween the second and third lens elements for dispersing light onto aproper level, which will improve the image quality, before the lightentering the third lens element. Shortening the air gap between thefourth and fifth lens elements will assist in shortening the length ofthe optical imaging lens. Therefore, it is suggested that the value ofAGL₂₃-AGL₄₅ is greater than or equal to 0 (mm), but not too large,preferably, between 0˜0.4 (mm) to satisfy equation (2).

Reference is now made to equation (3). The value of EFL/ALT ispreferable greater than or equal to 1.8. Shortening EFL is helpful toreduce the distance for focusing light and the length of the opticalimaging lens. However, EFL will change along with ALT. If EFL/ALT isgreater than 1.8, both EFL and ALT will be a proper value, preferably,EFL/ALT is between 1.9˜5.0 to satisfy equation (3) or (3′).

Reference is now made to equation (4). The value of CT₄/BFL ispreferable smaller than or equal to 0.7 to satisfy equation (4). This isbecause shortening CT₄ will help for shortening the length of theoptical imaging lens. The value of BFL is benefit to be controlled forreceiving an infrared cut filter. Preferably, CT₄/BFL satisfies Equation(4), and additionally it may be further restricted in 0.1˜0.5.

Reference is now made to equation (5). The value of ALT/BFL ispreferable smaller than or equal to 2.0 to satisfy equation (5). This isbecause shortening ALT will help for shortening the length of theoptical imaging lens to meet the modern trend. However, between thefifth lens element and an imaging plane (the distance between both alongthe optical axis is BFL), it may be required enough space for receivingan infrared cut filter for some implementations. Therefore, if the valueof ALT/BFL is greater than 2.0, this may be means an excessive ALT or ascarce BFL, and both fail to meet the modern trend. Preferably, ALT/BFLsatisfies Equation (5), and additionally it may be further restricted in0.2˜1.5.

Reference is now made to equation (6). The value of CT₄/AGL₂₃ ispreferable smaller than or equal to 3.0 to satisfy equation (6). This isbecause shortening CT₄ will help for shortening the length of theoptical imaging lens, and the value of AGL₂₃ is benefit to be controlledfor allowing the light dispersed onto a proper level before enteringinto the third lens element. Preferably, CT₄/AGL₂₃ may be furtherrestricted in 0.5˜3.0.

When implementing example embodiments, more details about the convex orconcave surface structure and/or the refracting power may beincorporated for one specific lens element or broadly for plural lenselements to enhance the control for the system performance and/orresolution, as illustrated in the following embodiments. It is notedthat the details listed here could be incorporated in exampleembodiments if no inconsistency occurs.

Several exemplary embodiments and associated optical data will now beprovided for illustrating example embodiments of optical imaging lenswith good optical characters and a shortened length. Reference is nowmade to FIGS. 1-5 . FIG. 1 illustrates an example cross-sectional viewof an optical imaging lens 1 having five lens elements of the opticalimaging lens according to a first example embodiment. FIG. 2 showsexample charts of longitudinal spherical aberration and other kinds ofoptical aberrations of the optical imaging lens 1 according to anexample embodiment. FIG. 3 depicts another example cross-sectional viewof a lens element of the optical imaging lens 1 according to an exampleembodiment. FIG. 4 illustrates an example table of optical data of eachlens element of the optical imaging lens 1 according to an exampleembodiment. FIG. 5 depicts an example table of a spherical data of theoptical imaging lens 1 according to an example embodiment.

As shown in FIG. 1 , the optical imaging lens 1 of the presentembodiment comprises, in order from an object side A1 to an image sideA2, an aperture stop 100 positioned before a first lens element 110, thefirst lens element 110, a second lens element 120, a third lens element130, a fourth lens element 140, a fifth lens element 150. A filteringunit 160 and an image plane 170 of an image sensor are positioned at theimage side A2 of the optical lens 1. Each of the first, second, third,fourth, fifth lens elements 110, 120, 130, 140, 150 and the filteringunit 160 has an object-side surface 111/121/131/141/151/161 facingtoward the object side A1 and an image-side surface112/122/132/142/152/162 facing toward the image side A2. The exampleembodiment of the filtering unit 160 illustrated is an IR cut filter(infrared cut filter) positioned between the fifth lens element 150 andan image plane 170. The filtering unit 160 selectively absorbs lightwith specific wavelength from the light passing optical imaging lens 1.For example, IR light is absorbed, and this will prohibit the IR lightwhich is not seen by human eyes from producing an image on the imageplane 170.

Exemplary embodiments of each lens elements of the optical imaging lens1 will now be described with reference to the drawings.

An example embodiment of the first lens element 110 may have positiverefracting power, which may be constructed by plastic material. Theobject-side surface 111 is a convex surface and the image-side surface112 is a concave surface.

The second lens element 120 may have negative refracting power, whichmay be constructed by plastic material. The object-side surface 121 is aconvex surface and the image-side surface 122 is a concave surface. Theobject-side surface 121 has a convex portion 1212 in a vicinity of aperiphery of the second lens element 120.

The third lens element 130 may have negative refracting power, which maybe constructed by plastic material. The object-side surface 131 is aconcave surface, and the image-side surface 132 is a convex surface.

The fourth lens element 140 may have positive refracting power, whichmay be constructed by plastic material. The object-side surface 141 is aconcave surface, and the image-side surface 142 is a convex surface. Theobject-side surface 141 has a concave portion 1412 in a vicinity of aperiphery of the fourth lens element 140.

The fifth lens element 150 may have negative refracting power, which maybe constructed by plastic material. The object-side surface 151 is aconcave surface. The image-side surface 152 has a concave portion 1521in a vicinity of the optical axis and a convex portion 1522 in avicinity of a periphery of the fifth lens element 150.

In example embodiments, air gaps exist between the lens elements 110,120, 130, 140, 150, the filtering unit 160, and the image plane 170 ofthe image sensor. For example, FIG. 1 illustrates the air gap d1existing between the first lens element 110 and the second lens element120, the air gap d2 existing between the second lens element 120 and thethird lens element 130, the air gap d3 existing between the third lenselement 130 and the fourth lens element 140, the air gap d4 existingbetween the fourth lens element 140 and the fifth lens element 150, theair gap d5 existing between the fifth lens element 150 and the filteringunit 160, and the air gap d6 existing between the filtering unit 160 andthe image plane 170 of the image sensor. However, in other embodiments,any of the aforesaid air gaps may or may not exist. For example, theprofiles of opposite surfaces of any two adjacent lens elements maycorrespond to each other, and in such situation, the air gap may notexist. The air gap d1 is denoted by AGL₁₂, the air gap d3 is denoted byAGL₃₄, and the sum of all air gaps d1, d2, d3, d4 between the first andfifth lens elements 110, 150 is denoted by AAG.

FIG. 4 depicts the optical characters of each lens elements in theoptical imaging lens 1 of the present embodiment, wherein the values ofAAG/CT₅, AGL₂₃-AGL₄₅, EFL/ALT, CT₄/BFL, ALT/BFL and CT₄/AGL₂₃ are:(AAG/CT ₅)=3.104,  satisfying equation (1);(AGL ₂₃-AGL ₄₅)=0.250 (mm),  satisfying equation (2);(EFL/ALT)=2.006,  satisfying equation (3), (3′);(CT ₄ /BFL)=0.414,  satisfying equation (4), (4′);(ALT/BFL)=1.369,  satisfying equation (5), (5′);(CT ₄ /AGL ₂₃)=1.268,  satisfying equation (6);

wherein the distance from the object-side convex surface 111 of thefirst lens element 110 to the image plane 170 is 4.876 (mm), and thelength of the optical imaging lens 1 is shortened.

Please note that, in example embodiments, to clearly illustrate thestructure of each lens element, only the part where light passes isshown. For example, taking the first lens element 110 as an example,FIG. 1 illustrates the object-side surface 111 and the image-sidesurface 112. However, when implementing each lens element of the presentembodiment, a fixing part for positioning the lens elements inside theoptical imaging lens 1 may be formed selectively. Based on the firstlens element 110, please refer to FIG. 3 , which illustrates the firstlens element 110 further comprising a fixing part. Here the fixing partis not limited to a protruding part 113 extending from the object-sideconvex surface 111 and the image-side surface 112 for mounting the firstlens element 110 in the optical imaging lens 1, and ideally, light willnot pass through the protruding part 113.

The spherical surfaces, including the object-side surface 111 and theimage-side surface 112 of the first lens element 110, the object-sidesurface 121 and the image-side surface 122 of the second lens element120, the object-side surface 131 and the image-side surface 132 of thethird lens element 130, the object-side surface 141 and the image-sidesurface 142 of the fourth lens element 140, and the object-side surface151 and the image-side surface 152 of the fifth lens element 150 are alldefined by the following aspherical formula:

${Z(Y)} = {{\frac{Y^{2}}{R}/\left( {1 + \sqrt{1 - {\left( {1 + K} \right)\frac{Y^{2}}{R^{2}}}}} \right)} + {\sum\limits_{i = 1}^{n}{a_{i} \times Y^{i}}}}$

-   -   wherein,    -   R represents the radius of the surface of the lens element;    -   Z represents the depth of the spherical surface (the        perpendicular distance between the point of the spherical        surface at a distance Y from the optical axis and the tangent        plane of the vertex on the optical axis of the spherical        surface);    -   Y represents the perpendicular distance between the point of the        spherical surface and the optical axis;    -   K represents a conic constant;    -   a_(i) represents a spherical coefficient of i^(th) level.

The values of each spherical parameter are shown in FIG. 5 .

As illustrated in FIG. 2 , the optical imaging lens 1 of the presentexample embodiment shows great characteristics in the longitudinalspherical aberration (a), astigmatism aberration in the sagittaldirection (b), astigmatism aberration in the tangential direction (c),and distortion aberration (d). Therefore, according to aboveillustration, the optical imaging lens 1 of the example embodimentindeed achieves great optical performance and the length of the opticalimaging lens 1 is effectively shortened.

Reference is now made to FIGS. 6-9 . FIG. 6 illustrates an examplecross-sectional view of an optical imaging lens 2 having five lenselements of the optical imaging lens according to a second exampleembodiment. FIG. 7 shows example charts of longitudinal sphericalaberration and other kinds of optical aberrations of the optical imaginglens 2 according to the second example embodiment. FIG. 8 shows anexample table of optical data of each lens element of the opticalimaging lens 2 according to the second example embodiment. FIG. 9 showsan example table of aspherical data of the optical imaging lens 2according to the second example embodiment. The reference numberslabeled in the present embodiment are similar to those in the firstembodiment for the similar elements, but here the reference numbers areinitialed with 2, for example, reference number 211 for labeling theobject-side surface of the first lens element 210, reference number 212for labeling the image-side surface of the first lens element 210, etc.

As shown in FIG. 6 , the optical imaging lens 2 of the presentembodiment, in an order from an object side A1 to an image side A2,comprises an aperture stop 200 positioned in front of a first lenselement 210, the first lens element 210, a second lens element 220, athird lens element 230, a fourth lens element 240, and a fifth lenselement 250.

The differences between the second embodiment and the first embodimentare the radius, thickness of each lens element and the distance of eachair gap, the transition of the refracting power and configuration of theconcave/convex shape of the lens elements are similar to those in thefirst embodiment. Please refer to FIG. 8 for the optical characteristicsof each lens elements in the optical imaging lens 2 of the presentembodiment, wherein the values of AAG/CT₅, AGL₂₃-AGL₄₅, EFL/ALT,CT₄/BFL, ALT/BFL and CT₄/AGL₂₃ are:(AAG/CT ₅)=3.441,  satisfying equation (1);(AGL ₂₃-AGL ₄₅)=0.050 (mm),  satisfying equation (2);(EFL/ALT)=1.936,  satisfying equation (3), (3′);(CT ₄ /BFL)=0.439,  satisfying equation (4), (4′);(ALT/BFL)=1.408,  satisfying equation (5), (5′);(CT ₄ /AGL ₂₃)=1.778,  satisfying equation (6);

wherein the distance from the object side surface 211 of the first lenselement 210 to the image plane 270 is 4.673 (mm) and the length of theoptical imaging lens 2 is shortened.

As shown in FIG. 7 , the optical imaging lens 2 of the presentembodiment shows great characteristics in longitudinal sphericalaberration (a), astigmatism in the sagittal direction (b), astigmatismin the tangential direction (c), and distortion aberration (d).Therefore, according to the above illustration, the optical imaging lensof the present embodiment indeed shows great optical performance and thelength of the optical imaging lens 2 is effectively shortened.

Reference is now made to FIGS. 10-13 . FIG. 10 illustrates an examplecross-sectional view of an optical imaging lens 3 having five lenselements of the optical imaging lens according to a third exampleembodiment. FIG. 11 shows example charts of longitudinal sphericalaberration and other kinds of optical aberrations of the optical imaginglens 3 according to the third example embodiment. FIG. 12 shows anexample table of optical data of each lens element of the opticalimaging lens 3 according to the third example embodiment. FIG. 13 showsan example table of a spherical data of the optical imaging lens 3according to the third example embodiment. The reference numbers labeledin the present embodiment are similar to those in the first embodimentfor the similar elements, but here the reference numbers are initialedwith 3, for example, reference number 311 for labeling the object-sidesurface of the first lens element 310, reference number 312 for labelingthe image-side surface of the first lens element 310, etc.

As shown in FIG. 10 , the optical imaging lens 3 of the presentembodiment, in an order from an object side A1 to an image side A2,comprises an aperture stop 300 positioned in front of a first lenselement 310, the first lens element 310, a second lens element 320, athird lens element 330, a fourth lens element 340, and a fifth lenselement 350.

The differences between the third embodiment and the first embodimentare the image-side surface 312 of the first lens element 310, whichhaving a convex portion 3121 in a vicinity of the optical axis and aconcave portion 3122 in a vicinity of a periphery of the first lenselement 310, and also the thickness of each lens element and thedistance of each air gap. Please refer to FIG. 12 for the opticalcharacteristics of each lens elements in the optical imaging lens 3 ofthe present embodiment, wherein the values of AAG/CT₅, AGL₂₃-AGL₄₅,EFL/ALT, CT₄/BFL, ALT/BFL and CT₄/AGL₂₃ are:(AAG/CT ₅)=3.100,  satisfying equation (1);(AGL ₂₃-AGL ₄₅)=0.320 (mm),  satisfying equation (2);(EFL/ALT)=1.994,  satisfying equation (3), (3′);(CT ₄ /BFL)=0.427,  satisfying equation (4), (4′);(ALT/BFL)=1.423,  satisfying equation (5), (5′);(CT ₄ /AGL ₂₃)=1.132,  satisfying equation (6);

wherein the distance from the object side surface 311 of the first lenselement 310 to the image plane 370 is 4.908 (mm) and the length of theoptical imaging lens 3 is shortened.

As shown in FIG. 11 , the optical imaging lens 3 of the presentembodiment shows great characteristics in longitudinal sphericalaberration (a), astigmatism in the sagittal direction (b), astigmatismin the tangential direction (c), and distortion aberration (d).Therefore, according to the above illustration, the optical imaging lensof the present embodiment indeed shows great optical performance and thelength of the optical imaging lens 3 is effectively shortened.

Reference is now made to FIGS. 14-17 . FIG. 14 illustrates an examplecross-sectional view of an optical imaging lens 4 having five lenselements of the optical imaging lens according to a fourth exampleembodiment. FIG. 15 shows example charts of longitudinal sphericalaberration and other kinds of optical aberrations of the optical imaginglens 4 according to the fourth embodiment. FIG. 16 shows an exampletable of optical data of each lens element of the optical imaging lens 4according to the fourth example embodiment. FIG. 17 shows an exampletable of a spherical data of the optical imaging lens 4 according to thefourth example embodiment. The reference numbers labeled in the presentembodiment are similar to those in the first embodiment for the similarelements, but here the reference numbers are initialed with 4, forexample, reference number 411 for labeling the object-side surface ofthe first lens element 410, reference number 412 for labeling theimage-side surface of the first lens element 410, etc.

As shown in FIG. 14 , the optical imaging lens 4 of the presentembodiment, in an order from an object side A1 to an image side A2,comprises an aperture stop 400 positioned in front of a first lenselement 410, the first lens element 410, a second lens element 420, athird lens element 430, a fourth lens element 440, and a fifth lenselement 450.

The differences between the fourth embodiment and the third embodimentare the radius and thickness of each lens element and the distance ofeach air gap, but the transition of the refracting power andconfiguration of the concave/convex shape of the lens elements aresimilar to those in the third embodiment. Please refer to FIG. 16 forthe optical characteristics of each lens elements in the optical imaginglens 4 of the present embodiment, wherein the values of AAG/CT₅,AGL₂₃-AGL₄₅, EFL/ALT, CT₄/BFL, ALT/BFL and CT₄/AGL₂₃ are:(AAG/CT ₅)=4.098,  satisfying equation (1);(AGL ₂₃-AGL ₄₅)=0.182 (mm),  satisfying equation (2);(EFL/ALT)=2.054,  satisfying equation (3), (3′);(CT ₄ /BFL)=0.423,  satisfying equation (4), (4′);(ALT/BFL)=1.338,  satisfying equation (5), (5′);(CT ₄ /AGL ₂₃)=1.351,  satisfying equation (6);

wherein the distance from the object side surface 411 of the first lenselement 410 to the image plane 470 is 4.854 (mm) and the length of theoptical imaging lens 4 is shortened.

As shown in FIG. 15 , the optical imaging lens 4 of the presentembodiment shows great characteristics in longitudinal sphericalaberration (a), astigmatism in the sagittal direction (b), astigmatismin the tangential direction (c), and distortion aberration (d).Therefore, according to the above illustration, the optical imaging lensof the present embodiment indeed shows great optical performance and thelength of the optical imaging lens 4 is effectively shortened.

Reference is now made to FIGS. 18-21 . FIG. 18 illustrates an examplecross-sectional view of an optical imaging lens 5 having five lenselements of the optical imaging lens according to a fifth exampleembodiment. FIG. 19 shows example charts of longitudinal sphericalaberration and other kinds of optical aberrations of the optical imaginglens 5 according to the fifth embodiment. FIG. 20 shows an example tableof optical data of each lens element of the optical imaging lens 5according to the fifth example embodiment. FIG. 21 shows an exampletable of a spherical data of the optical imaging lens 5 according to thefifth example embodiment. The reference numbers labeled in the presentembodiment are similar to those in the first embodiment for the similarelements, but here the reference numbers are initialed with 5, forexample, reference number 511 for labeling the object-side surface ofthe first lens element 510, reference number 512 for labeling theimage-side surface of the first lens element 510, etc.

As shown in FIG. 18 , the optical imaging lens 5 of the presentembodiment, in an order from an object side A1 to an image side A2,comprises an aperture stop 500 positioned in front of a first lenselement 510, the first lens element 510, a second lens element 520, athird lens element 530, a fourth lens element 540, and a fifth lenselement 550.

The differences between the fifth embodiment and the third embodimentare the radius, thickness of each lens element, and the distance of eachair gap, but the transition of the refracting power and theconfiguration of the concave-convex shape of the lens elements aresimilar to those in the third embodiment. Please refer to FIG. 20 forthe optical characteristics of each lens elements in the optical imaginglens 5 of the present embodiment, wherein the values of AAG/CT₅,AGL₂₃-AGL₄₅, EFL/ALT, CT₄/BFL, ALT/BFL and CT₄/AGL₂₃ are:(AAG/CT ₅)=4.084,  satisfying equation (1);(AGL ₂₃-AGL ₄₅)=0.182 (mm),  satisfying equation (2);(EFL/ALT)=2.053,  satisfying equation (3), (3′);(CT ₄ /BFL)=0.423,  satisfying equation (4), (4′);(ALT/BFL)=1.339,  satisfying equation (5), (5′);(CT ₄ /AGL ₂₃)=1.352,  satisfying equation (6);

wherein the distance from the object side surface 511 of the first lenselement 510 to the image plane 570 is 4.853 (mm) and the length of theoptical imaging lens 5 is shortened.

As shown in FIG. 19 , the optical imaging lens 5 of the presentembodiment shows great characteristics in longitudinal sphericalaberration (a), astigmatism in the sagittal direction (b), astigmatismin the tangential direction (c), and distortion aberration (d).Therefore, according to the above illustration, the optical imaging lensof the present embodiment indeed shows great optical performance and thelength of the optical imaging lens 5 is effectively shortened.

Reference is now made to FIGS. 22-25 . FIG. 22 illustrates an examplecross-sectional view of an optical imaging lens 6 having five lenselements of the optical imaging lens according to a sixth exampleembodiment. FIG. 23 shows example charts of longitudinal sphericalaberration and other kinds of optical aberrations of the optical imaginglens 6 according to the sixth embodiment. FIG. 24 shows an example tableof optical data of each lens element of the optical imaging lens 6according to the sixth example embodiment. FIG. 25 shows an exampletable of a spherical data of the optical imaging lens 6 according to thesixth example embodiment. The reference numbers labeled in the presentembodiment are similar to those in the first embodiment for the similarelements, but here the reference numbers are initialed with 6, forexample, reference number 611 for labeling the object-side surface ofthe first lens element 610, reference number 612 for labeling theimage-side surface of the first lens element 610, etc.

As shown in FIG. 22 , the optical imaging lens 6 of the presentembodiment, in an order from an object side A1 to an image side A2,comprises an aperture stop 600 positioned in front of a first lenselement 610, the first lens element 610, a second lens element 620, athird lens element 630, a fourth lens element 640, and a fifth lenselement 650.

The differences between the sixth embodiment and the third embodimentare the thickness of each lens element and the distance of each air gap,but the transition of the refracting power and configuration of theconcave/convex shape of the lens elements are similar to those in thethird embodiment. Please refer to FIG. 24 for the opticalcharacteristics of each lens elements in the optical imaging lens 6 ofthe present embodiment, wherein the values of AAG/CT₅, AGL₂₃-AGL₄₅,EFL/ALT, CT₄/BFL, ALT/BFL and CT₄/AGL₂₃ are:(AAG/CT ₅)=3.415,  satisfying equation (1);(AGL ₂₃-AGL ₄₅)=0.201 (mm),  satisfying equation (2);(EFL/ALT)=2.050,  satisfying equation (3), (3′);(CT ₄ /BFL)=0.397,  satisfying equation (4), (4′);(ALT/BFL)=1.297,  satisfying equation (5), (5′);(CT ₄ /AGL ₂₃)=1.374,  satisfying equation (6);

wherein the distance from the object side surface 611 of the first lenselement 610 to the image plane 670 is 4.926 (mm) and the length of theoptical imaging lens 6 is shortened.

As shown in FIG. 23 , the optical imaging lens 6 of the presentembodiment shows great characteristics in longitudinal sphericalaberration (a), astigmatism in the sagittal direction (b), astigmatismin the tangential direction (c), and distortion aberration (d).Therefore, according to the above illustration, the optical imaging lensof the present embodiment indeed shows great optical performance and thelength of the optical imaging lens 6 is effectively shortened.

Please refer to FIG. 26 , which shows the values of AAG/CT₅,AGL₂₃-AGL₄₅, EFL/ALT, CT₄/BFL, ALT/BFL and CT₄/AGL₂₃ of all sixembodiments, and it is clear that the optical imaging lens of thepresent invention satisfy the Equations (1), (2), (3)/(3′), (4)/(4′),(5)/(5′), (6).

Reference is now made to FIG. 27 , which illustrates an examplestructural view of a first embodiment of mobile device 20 applying anaforesaid optical imaging lens. The mobile device 20 comprises a housing21 and a photography module 22 positioned in the housing 21. An exampleof the mobile device 20 may be, but is not limited to, a mobile phone.

As shown in FIG. 27 , the photography module 22 may comprise anaforesaid optical imaging lens with five lens elements, for example theoptical imaging lens 1 of the first embodiment, a lens barrel 23 forpositioning the optical imaging lens 1, a module housing unit 24 forpositioning the lens barrel 23, a substrate 172 for positioning themodule housing unit 24, and an image sensor 171 which is positioned atan image side of the optical imaging lens 1. The image plane 170 isformed on the image sensor 171.

In some other example embodiments, the structure of the filtering unit160 may be omitted. In some example embodiments, the housing 21, thelens barrel 23, and/or the module housing unit 24 may be integrated intoa single component or assembled by multiple components. In some exampleembodiments, the image sensor 171 used in the present embodiment isdirectly attached to a substrate 172 in the form of a chip on board(COB) package, and such package is different from traditional chip scalepackages (CSP) since COB package does not require a cover glass beforethe image sensor 171 in the optical imaging lens 1. Aforesaid exemplaryembodiments are not limited to this package type and could beselectively incorporated in other described embodiments.

The five lens elements 110, 120, 130, 140, 150 are positioned in thelens barrel 23 in the way of separated by an air gap between any twoadjacent lens elements.

The module housing unit 24 comprises a seat element 2401 for positioningthe lens barrel 23. The lens barrel 23 and the seat element 2401 arepositioned along a same axis I-I′, and the lens barrel 23 is positionedinside the seat element 2401.

Because the length of the optical imaging lens 1 is merely 4.876 (mm),the size of the mobile device 20 may be quite small. Therefore, theembodiments described herein meet the market demand for smaller sizedproduct designs.

Reference is now made to FIG. 28 , which shows another structural viewof a second embodiment of mobile device 20′ applying the aforesaidoptical imaging lens 1. One difference between the mobile device 20′ andthe mobile device 20 may be the seat element 2401 comprises a first seatunit 2402, a second seat unit 2403, a coil 2404, and a magnetic unit2405. Here, the second seat unit 2403 of the seat element 2401 couldmove along the optical axis of the optical imaging lens 1. Please referto the details as follows. The first seat unit 2402 is close to theoutside of the lens barrel 23, and positioned along an axis I-I′, andthe second seat unit 2403 is around the outside of the first seat unit2402 and positioned along with the axis I-I′. The coil 2404 ispositioned between the first seat unit 2402 and the inside of the secondseat unit 2403. The magnetic unit 2405 is positioned between the outsideof the coil 2404 and the inside of the second seat unit 2403.

The lens barrel 23 and the optical imaging lens 1 positioned therein aredriven by the first seat unit 2402 for moving along the axis I-I′. Therest structure of the mobile device 20′ is similar to the mobile device20.

Similarly, because the length of the optical imaging lens 1, 4.876 (mm),is shortened, the mobile device 20′ may be designed with a smaller sizeand meanwhile good optical performance is still provided. Therefore, thepresent embodiment meets the demand of small sized product design andthe request of the market.

According to above illustration, it is clear that the mobile device andthe optical imaging lens thereof in example embodiments, throughcontrolling ratio of at least one central thickness of lens element to asum of all air gaps along the optical axis between five lens elements ina predetermined range, and incorporated with detail structure and/orreflection power of the lens elements, the length of the optical imaginglens is effectively shortened and meanwhile good optical characters arestill provided.

While various embodiments in accordance with the disclosed principleshave been described above, it should be understood that they have beenpresented by way of example only, and are not limiting. Thus, thebreadth and scope of exemplary embodiment(s) should not be limited byany of the above-described embodiments, but should be defined only inaccordance with the claims and their equivalents issuing from thisdisclosure. Furthermore, the above advantages and features are providedin described embodiments, but shall not limit the application of suchissued claims to processes and structures accomplishing any or all ofthe above advantages.

Additionally, the section headings herein are provided for consistencywith the suggestions under 37 C.F.R. 1.77 or otherwise to provideorganizational cues. These headings shall not limit or characterize theinvention(s) set out in any claims that may issue from this disclosure.Specifically, a description of a technology in the “Background” is notto be construed as an admission that technology is prior art to anyinvention(s) in this disclosure. Furthermore, any reference in thisdisclosure to “invention” in the singular should not be used to arguethat there is only a single point of novelty in this disclosure.Multiple inventions may be set forth according to the limitations of themultiple claims issuing from this disclosure, and such claimsaccordingly define the invention(s), and their equivalents, that areprotected thereby. In all instances, the scope of such claims shall beconsidered on their own merits in light of this disclosure, but shouldnot be constrained by the headings herein.

What is claimed is:
 1. An optical imaging lens, sequentially from anobject side to an image side, comprising first, second, third, fourthand fifth lens elements, each of the first, second, third, fourth andfifth lens elements having an object-side surface facing toward theobject side and an image-side surface facing toward the image side,wherein: the image-side surface of the first lens element comprises aconcave portion in a vicinity of a periphery of the first lens element;the image-side surface of the second lens element comprises a concaveportion in a vicinity of an optical axis; the image-side surface of thefifth lens element comprises a concave portion in a vicinity of theoptical axis; the optical imaging lens as a whole having a total of fivelens elements; a sum of a central thickness of the second lens elementalong the optical axis and a central thickness of the fifth lens elementalong the optical axis is greater than an air gap between the fourthlens element and the fifth lens element along the optical axis; and aneffective focal length of the optical imaging lens is EFL, a sum ofthicknesses of all five lens elements along the optical axis is ALT, acentral thickness of the fourth lens element along the optical axis isCT4, a back focal length of the optical imaging lens is BFL, and EFL,ALT, CT4 and BFL satisfy the equations:EFL/ALT≥1.9, andCT ₄ /BFL≤0.7.
 2. The optical imaging lens according to claim 1, whereinCT4 and BFL further satisfy the equation:CT ₄ /BFL≤0.5.
 3. The optical imaging lens according to claim 1, whereinALT and BFL satisfy the equation:ALT/BFL≤2.0.
 4. The optical imaging lens according to claim 1, wherein asum of all four air gaps from the first lens element to the fifth lenselement along the optical axis is AAG, a central thickness of the fifthlens element along the optical axis is CT5, and AAG and CT5 satisfy theequation:AAG/CT ₅≥3.0.
 5. The optical imaging lens according to claim 1, whereinan air gap between the second lens element and the third lens elementalong the optical axis is AGL23, and CT4 and AGL23 satisfy the equation:CT ₄ /AGL ₂₃≤3.0.
 6. The optical imaging lens according to claim 1,wherein an Abbe number of the first lens element is greater than a sumof an Abbe number of the second lens element and an Abbe number of thethird lens element.
 7. An optical imaging lens, sequentially from anobject side to an image side, comprising first, second, third, fourthand fifth lens elements, each of the first, second, third, fourth andfifth lens elements having an object-side surface facing toward theobject side and an image-side surface facing toward the image side,wherein: the image-side surface of the first lens element comprises aconcave portion in a vicinity of a periphery of the first lens element;the object-side surface of the second lens element comprises a convexportion in a vicinity of a periphery of the second lens element, and theimage-side surface of the second lens element comprises a concaveportion in a vicinity of an optical axis; the image-side surface of thefourth lens element comprises a convex portion in a vicinity of aperiphery of the fourth lens element; the optical imaging lens as awhole having a total of five lens elements; and an effective focallength of the optical imaging lens is EFL, a sum of thicknesses of allfive lens elements along the optical axis is ALT, and EFL and ALTsatisfy the equation:EFL/ALT≥1.9.
 8. The optical imaging lens according to claim 7, wherein acentral thickness of the fourth lens element along the optical axis isCT4, a back focal length of the optical imaging lens is BFL, and CT4 andBFL satisfy the equation:CT ₄ /BFL≤0.7.
 9. The optical imaging lens according to claim 7, whereina back focal length of the optical imaging lens is BFL, and ALT and BFLsatisfy the equation:ALT/BFL≤1.5.
 10. The optical imaging lens according to claim 7, whereina sum of all four air gaps from the first lens element to the fifth lenselement along the optical axis is AAG, a central thickness of the fifthlens element along the optical axis is CT5, and AAG and CT5 satisfy theequation:AAG/CT ₅≥3.0.
 11. The optical imaging lens according to claim 7, whereina sum of a central thickness of the first lens element along the opticalaxis and a central thickness of the fifth lens element along the opticalaxis is greater than an air gap between the fourth lens element and thefifth lens element along the optical axis.
 12. The optical imaging lensaccording to claim 7, wherein a central thickness of the first lenselement along the optical axis is greater than an air gap between thefourth lens element and the fifth lens element along the optical axis.13. The optical imaging lens according to claim 7, wherein an abbenumber of the fourth lens element is greater than a sum of an abbenumber of the second lens element and an abbe number of the third lenselement.
 14. An optical imaging lens, sequentially from an object sideto an image side, comprising first, second, third, fourth and fifth lenselements, each of the first, second, third, fourth and fifth lenselements having an object-side surface facing toward the object side andan image-side surface facing toward the image side, wherein: theimage-side surface of the first lens element comprises a concave portionin a vicinity of a periphery of the first lens element; the image-sidesurface of the second lens element comprises a concave portion in avicinity of an optical axis, and the object-side surface of the secondlens element comprises a convex portion in a vicinity of a periphery ofthe second lens element; the image-side surface of the third lenselement comprises a convex portion in the vicinity of the optical axis;the optical imaging lens as a whole having a total of five lenselements; and an effective focal length of the optical imaging lens isEFL, a sum of thicknesses of all five lens elements along the opticalaxis is ALT, and EFL and ALT satisfy the equations:EFL/ALT≥1.9.
 15. The optical imaging lens according to claim 14, whereina central thickness of the fourth lens element along the optical axis isCT4, a back focal length of the optical imaging lens is BFL, and CT4 andBFL satisfy the equation:CT ₄ /BFL≤0.7.
 16. The optical imaging lens according to claim 14,wherein a back focal length of the optical imaging lens is BFL, and ALTand BFL satisfy the equation:ALT/BFL≤2.0.
 17. The optical imaging lens according to claim 14, whereinan air gap between the second lens element and the third lens elementalong the optical axis is AGL23, an air gap between the fourth lenselement and the fifth lens element along the optical axis is AGL45, andAGL23 and AGL45 satisfy the equation:0 mm≤AGL ₂₃ −AGL ₄₅≤0.4 mm.
 18. The optical imaging lens according toclaim 14, wherein a sum of a central thickness of the first lens elementalong the optical axis and a central thickness of the second lenselement along the optical axis is greater than an air gap between thefourth lens element and the fifth lens element along the optical axis.19. The optical imaging lens according to claim 14, wherein an Abbenumber of the fifth lens element is greater than a sum of an Abbe numberof the second lens element and an Abbe number of the third lens element.